The Second World War was caused by much anger and resentment between countries after the first war. There were causes such as the Treaty of Versailles, which led to the rise of Hitler. Other causes were Japanese imperialism and the Munich Agreement. Appeasement played a role in allowing Hitler to invade many territories, and gain control of many countries in the war. World War II began in 1939, when the United States was struggling through the Great Depression, and didn't come to an end until 1945.
The Treaty of Versailles was one of the causes of World War II, which led to the rise of Adolph Hitler. The document placed the blame of World War I on Germany. Germany had to pay reparations for all the damage of the war, leading them to a huge economic downfall. Diminishing their military defenses was also agreed to take place, according to the Treaty of Versailles. Hitler and the rest of Germany were no pleased to be informed of the humiliation Germany was facing. As a result of this anger, Hitler was determined to become the highest power and overrule any obstacles that lay ahead of Germany. As another effect of the Treaty of Versailles, Italy was angered by them not being granted the land they were promised. This made them motivated to join hands with any country that would be supportive of their resentment. .
The United States never signed the Treaty of Versailles, mostly because the congressmen would not want to join in the League of Nations. Isolationism was the United States' policy after World War I, as they didn't want any risk of tangled alliances, the cause of the First World War, to harm their national sovereignty. Another such cause of World War II was the fact that United States lent money to Britain and France, because the U.S. felt bad for Europe after World War I. It was almost like one big triangle. The United States lent money to Britain and France, and demanded that the debt be repaid.